Printed circuit (PC) boards or cards are well known and widely used in various electrical applications. Typically, a PC board comprises a flat rectangular sheet of insulating material, such as glass-fibre reinforced resin, with a number of circuit components mounted thereon and electrical contacts along one edge of the board. It is common to assemble a plurality of PC boards in a closely-spaced parallel relationship in an electronic chassis or card cage, which removably supports the PC boards in parallel slots. A card cage generally contains a backplane having a plurality of electric connectors and card guides or tracks for PC boards to be inserted into the card cage. Inserting a PC board into a card cage along a card guide so that the board's electrical contacts mate with a connector in the backplane of the card cage seats a PC board into the backplane. A plurality of PC boards become interconnected in a card cage when each PC board is fully seated into the backplane of the card cage.
Seating a PC board into and extracting it from a card cage can be difficult because of the tight board-to-board spacing. It is hard to apply the right amount of force in the typically small space available for grasping with a human hand. In addition, because of the small space, the force applied may deviate from the straight linearity, which may impose bending stresses on the board and cause damage to the board.
Various devices have been developed to assist insertion and extraction of PC boards into and from card cages. Many of these devices are developed only for insertion or extraction, but not both. U.S. Pat. No. 4,403,408 to Koppensteiner, et al. describes such a device. For those that are capable of assisting both the insertion and extraction of a PC board into and from a card cage, it is very often required to mount the device onto the PC board. An example of such a device is disclosed in U.S. Pat. No. 5,506,758 to Cromwell. The mounting of a board inserter or extractor onto the board increases the width of the board, which renders fewer boards capable of being assembled in a card cage. Furthermore, these devices are not cost efficient because every board would require its own inserter or extractor.
Accordingly, there exists a need for a simple and low cost device for facilitating the insertion and extraction of a PC board into and from a card cage. The device should also be capable of facilitating the insertion and extraction of PC boards without being attached to the boards.